Challenges to the Clinical Integration of Transthoracic Three-Dimensional Echocardiography

Abstract

One of the most important transformations in echocardiography over the past decade has been the widespread adoption of three-dimensional (3D) transesophageal echocardiography (TEE) for evaluation of the mitral valve. This acceptance occurred after the introduction of the matrix array transducer, which streamlined data acquisition, allowing practical clinical acquisition times and visualization of acquired 3DE images in real-time [1]. The quality of these images is high in the majority of patients, facilitating training, interpretation and the clinical use of these images. These advantages led to the performance of multiple studies, which demonstrated improved clinical diagnosis with their use and so became part of societal guideline recommendations [2]. With increasing user-friendliness with this technology, many centers have expanded the use of 3D TEE to include the peri-procedural monitoring, assessment and guidance of a variety of transcatheter procedures [3]. In contrast to the widespread implementation of 3D TEE, 3D transthoracic echocardiography (TTE) has not experienced a similar increase in clinical use. This is despite many studies demonstrating its value in improving the assessment of left ventricular size and function, which is one of the core requests of most echocardiography laboratories [4–6]. For many years, one of the major limitations to the integration of 3D TTE into routine clinical practice was the requirement to change probes mid-study to acquire 3D images. With the development of transthoracic transducers that allow acquisition of both two-dimensional (2D) and 3DE images using a single probe, a more practical and rapid clinical workflow has become possible. More importantly, the 2D echocardiographic (2DE) image quality obtained from these combined 2D/3D probes are of equal quality to that of previously dedicated 2D probes. However, for 3D TTE to gain similar clinical acceptance to 3D TEE, additional technical improvements in 3D echocardiographic transducers and systems/software need to be developed. These areas include: 1) improvements in spatial and temporal resolution without increasing acquisition or post-processing time; 2) development of automated software that provides quantification of 3D echocardiographic datasets and is integrated into reporting systems; and 3) improvement of storage of 3D echocardiography datasets and analytical results into current reporting systems.